Well, it sucks if your grandparents die when you're very young. I was ~10 when my maternal grandfather died, and that was rubbish. I look back fondly on my time with him, but it's pretty lame that I never knew him outside of a child's experience - I never had the chance to have any grown up conversations/to ask him about his life in a way I'd like to have when looking back/etc.
My grandparents were almost all dead before I was older enough to remember except one who hated children. I don't see it as a big issue. Much more important issues like good loving parents, safe family environment, good school etc.
You also have to factor increaisng life expectancy, it is now much more likely the grandparents will be around in their 80s